Activation of prolyl hydroxylase-2 for stabilization of mitochondrial stress along with simultaneous downregulation of HIF-1α/FASN in ER + breast cancer subtype

Hypoxia induced lactate acidosis modulates tumor microenvironment and lipid reprogramming to sustain the cancer cell survival

It is well known that solid hypoxic tumour cells oxidise glucose through glycolysis, and the end product of this pathway is fermented into lactate which accumulates in the tumour microenvironment (TME). Initially, it was proclaimed that cancer cells cannot use lactate; therefore, they dump it into the TME and subsequently augment the acidity of the tumour milieu. Furthermore, the TME acts as a lactate sink with stope variable amount of lactate in different pathophysiological condition. Regardless of the amount of lactate pumped out within TME, it disappears immediately which still remains an unresolved puzzle. Recent findings have paved pathway in exploring the main role of lactate acidosis in TME. Cancer cells utilise lactate in the de novo fatty acid synthesis pathway to initiate angiogenesis and invasiveness, and lactate also plays a crucial role in the suppression of immunity. Furthermore, lactate re-programme the lipid biosynthetic pathway to develop a metabolic symbiosis in normoxic, moderately hypoxic and severely hypoxic cancer cells. For instance: severely hypoxic cancer cells enable to synthesizing poly unsaturated fatty acids (PUFA) in oxygen scarcity secretes excess of lactate in TME. Lactate from TME is taken up by the normoxic cancer cells whereas it is converted back to PUFAs after a sequence of reactions and then liberated in the TME to be utilized in the severely hypoxic cancer cells. Although much is known about the role of lactate in these biological processes, the exact molecular pathways that are involved remain unclear. This review attempts to understand the molecular pathways exploited by lactate to initiate angiogenesis, invasiveness, suppression of immunity and cause re-programming of lipid synthesis. This review will help the researchers to develop proper understanding of lactate associated bimodal regulations of TME.

NF-κB mediated regulation of tumor cell proliferation in hypoxic microenvironment

Hypoxia is caused by a cancer-promoting milieu characterized by persistent inflammation. NF-κB and HIF-1α are critical participants in this transition. Tumor development and maintenance are aided by NF-κB, while cellular proliferation and adaptability to angiogenic signals are aided by HIF-1α. Prolyl hydroxylase-2 (PHD-2) has been hypothesized to be the key oxygen-dependent regulator of HIF-1α and NF-transcriptional B's activity. Without low oxygen levels, HIF-1α is degraded by the proteasome in a process dependent on oxygen and 2-oxoglutarate. As opposed to the normal NF-κB activation route, where NF-κB is deactivated by PHD-2-mediated hydroxylation of IKK, this method actually activates NF-κB. HIF-1α is protected from degradation by proteasomes in hypoxic cells, where it then activates transcription factors involved in cellular metastasis and angiogenesis. The Pasteur phenomenon causes lactate to build up inside the hypoxic cells. As part of a process known as lactate shuttle, MCT-1 and MCT-4 cells help deliver lactate from the blood to neighboring, non-hypoxic tumour cells. Non-hypoxic tumour cells use lactate, which is converted to pyruvate, as fuel for oxidative phosphorylation. OXOPHOS cancer cells are characterized by a metabolic switch from glucose-facilitated oxidative phosphorylation to lactate-facilitated oxidative phosphorylation. Although PHD-2 was found in OXOPHOS cells. There is no clear explanation for the presence of NF-kappa B activity. The accumulation of the competitive inhibitor of 2-oxo-glutarate, pyruvate, in non-hypoxic tumour cells is well established. So, we conclude that PHD-2 is inactive in non-hypoxic tumour cells due to pyruvate-mediated competitive suppression of 2-oxo-glutarate. This results in canonical activation of NF-κB. In non-hypoxic tumour cells, 2-oxoglutarate serves as a limiting factor, rendering PHD-2 inactive. However, FIH prevents HIF-1α from engaging in its transcriptional actions. Using the existing scientific literature, we conclude in this study that NF-κB is the major regulator of tumour cell growth and proliferation via pyruvate-mediated competitive inhibition of PHD-2.

Regulation of Transactivation at C-TAD Domain of HIF-1α by Factor-Inhibiting HIF-1α (FIH-1): A Potential Target for Therapeutic Intervention in Cancer

Hypoxia-inducible factor-1alpha (HIF-1α) is a major transcription factor that adapts to low oxygen homeostasis and regulates the expression of several hypoxic genes, which aid in cancer survival and development. It has recently piqued the interest of translational researchers in the disciplines of cancer sciences. Hypoxia triggers an ample adaptive mechanism mediated via the HIF-1α transcriptional domain. Anaerobic glycolysis, angiogenesis, metastasis, and mitophagy are adaptive mechanisms that support tumor survival by promoting oxygen supply and regulating oxygen demand in hypoxic tumor cells. Throughout this pathway, the factor-inhibiting HIF-1α is a negative regulator of HIF-1α leading to its hydroxylation at the C-TAD domain of HIF-1α under normoxia. Thus, hydroxylated HIF-1α is unable to proceed with the transcriptional events due to interference in binding of C-TAD and CBP/p300. From this review, we can hypothesize that remodeling of FIH-1 activity is a unique mechanism that decreases the transcriptional activity of HIF-1α and, as a result, all of its hypoxic consequences. Hence, this review manuscript details the depth of knowledge of FIH-1 on hypoxia-associated cellular and molecular events, a potential strategy for targeting hypoxia-induced malignancies.

Effects of Excessive Activation of N-methyl-D-aspartic Acid Receptors in Neonatal Cardiac Mitochondrial Dysfunction Induced by Intrauterine Hypoxia

Intrauterine hypoxia is a common complication during pregnancy and could increase the risk of cardiovascular disease in offspring. However, the underlying mechanism is controversial. Memantine, an NMDA receptor antagonist, is reported to be a potential cardio-protective agent. We hypothesized that antenatal memantine treatment could prevent heart injury in neonatal offspring exposed to intrauterine hypoxia. Pregnant rats were exposed to gestational hypoxia or antenatal memantine treatment during late pregnancy. Newborns were then sacrificed to assess multiple parameters. The results revealed that Intrauterine hypoxia resulted in declining birth weight, heart weight, and an abnormally high heart weight/birth weight ratio. Furthermore, intrauterine hypoxia caused mitochondrial structural, functional abnormalities and decreased expression of DRP1, and upregulation of NMDAR1 in vivo. Antenatal memantine treatment,an NMDARs antagonist, improved these changes. In vitro, hypoxia increased the glutamate concentration and expression of NMDAR1. NMDAR activation may lead to similar changes in mitochondrial function, structure, and downregulation of DRP1 in vitro. Pharmacological blockade of NMDARs by the non-competitive NMDA antagonist MK-801 or knockdown of the glutamate receptor NR1 significantly attenuated the increased mitochondrial reactive oxygen species and calcium overload-induced by hypoxia exposure. These facts suggest that memantine could provide a novel and promising treatment for clinical use in intrauterine hypoxia during pregnancy to protect the cardiac mitochondrial function in the offspring. To our best knowledge, our research is the first study that shows intrauterine hypoxia can excessively activate cardiac NMDARs and thus cause mitochondrial dysfunction.

Repurposing Combination Therapy of Voacamine With Vincristine for Downregulation of Hypoxia-Inducible Factor-1α/Fatty Acid Synthase Co-axis and Prolyl Hydroxylase-2 Activation in ER+ Mammary Neoplasia

The current study investigated the role of combination therapy with voacamine and vincristine in preventing mammary gland carcinoma through prolyl hydroxylase-2 activation. Prolyl hydroxylase-2 activation leads to the downregulation of hypoxia-inducible factor-1α and fatty acid synthase. Overexpression of hypoxia-inducible factor-1α and fatty acid synthase has been previously reported in solid tumors of the mammary gland. After screening a battery of natural compounds similar to vincristine, voacamine was selected as a possible prolyl hydroxylase-2 activator, and its activity was evaluated using a 7,12-dimethylbenz[a]anthracene-induced rat model. The combination therapy was evaluated for cardiac toxicity using a hemodynamic profile. Angiogenic markers were evaluated by carmine staining. Monotherapy and combination therapy were also evaluated for liver and kidney toxicity using hematoxylin and eosin staining. The antioxidant potential was delineated using oxidative stress markers. The serum metabolomic profile was studied using NMR spectroscopy, and the disruption of fatty acids was evaluated using gas chromatography. Western blotting of proteins involved in hypoxic pathways was performed to decipher the action of therapy at the molecular level. Immunoblotting analysis validated that combination therapy has potential toss with prolyl hydroxylase-2 activity and thus initiates proteolytic degradation of hypoxia-inducible factor-1α and its consequent effects. Combination therapy also stimulated programmed cell death (apoptosis) in rapidly dividing cancer cells. The present study explored the role of voacamine inactivation of prolyl hydroxylase-2, which can decrease the overexpression of hypoxia-inducible factor-1α and fatty acid synthase in mammary gland carcinoma cells.

Effect of Voacamine upon inhibition of hypoxia induced fatty acid synthesis in a rat model of methyln-nitrosourea induced mammary gland carcinoma

BACKGROUND

In the present study, fatty acid synthesis is targeted to combat mammary gland carcinoma by activating prolyl hydroxylase-2 with Voacamine alone and in combination with Tamoxifen. It was hypothesized that the activation of prolyl hydroxylase-2 would inhibit the hypoxia-induced fatty acid synthesis and mammary gland carcinoma. Mammary gland carcinoma was induced with a single dose administration of N-methyl-N-nitrosourea (50 mg/kg,i.p.) and treatment with Voacamine and Tamoxifen 15 days after carcinogen administration.

RESULTS

At the end of the study, hemodynamic profiling of animals was recorded to assess the cardiotoxic potential of the drug. Blood serum was separated and subjected to nuclear magnetic resonance spectroscopy. Carmine staining and histopathology of mammary gland tissue were performed to evaluate the anti-angiogenic potential of the drug. The antioxidant potential of the drug was measured with antioxidant markers. Western blotting was performed to study the effect of the drug at the molecular level.

CONCLUSION

Results of the study have shown that Voacamine treatment stopped further decrease in body weight of experimental animals. The hemodynamic study evidenced that Voacamine at a low dose is safe in cardiac patients. Microscopic evaluation of mammary gland tissue documented the anti-angiogenic potential of Voacamine and Tamoxifen therapy. Perturbed serum metabolites were also restored to normal along with antioxidant markers. Immunoblotting of mammary gland tissue also depicted restoration of proteins of the hypoxic and fatty acid pathway. Conclusively, Voacamine and its combination with Tamoxifen activated prolyl hydroxylase-2 to combat mammary gland carcinoma.

Chemoprophylactic activity of nitazoxanide in experimental model of mammary gland carcinoma in rats

The current study focuses on the evaluation of the chemoprophylactic activity of nitazoxanide against the mammary gland carcinoma in experimental rats. The experimental protocol involves total 50 female Wistar albino rats of body weight 120-150 g, which were randomly categorized into five groups; Normal control (1% w/v carboxymethyl cellulose, p.o.); Toxic control (N-methyl-N-nitrosourea, MNU, 47 mg/kg i.v.); Standard (MNU, 47 mg/kg i.v. + tamoxifen, 1 mg/kg p.o.); Treatment 1 (MNU, 47 mg/kg i.v. + NTZ low-dose, 25 mg/kg p.o.); and Treatment 2 (MNU, 47 mg/kg, i.v. + NTZ high-dose, 50 mg/kg p.o.). The mammary gland carcinoma was induced by a single tail vein intravenous injection of MNU at a 47 mg/kg dose. Seven days after MNU administration, daily dosing of nitazoxanide and tamoxifen was initiated till 110th day in respective groups. The MNU toxicity was apparent with the altered electrocardiogram and heart rate variability, increased number of alveolar bud count, differentiation score, and upregulated antioxidant parameters. Nitazoxanide treatment restored the histological architecture in rats along with the reduction of alveolar buds and downregulation of oxidative stress markers as well as inflammatory markers. Therefore, nitazoxanide can be utilized as a potential chemoprophylactic agent against mammary gland carcinoma induced by MNU.

Roflumilast counteracts DMH-induced preneoplastic colon damage in albino Wistar rats

OBJECTIVE

The study explored the chemoprophylactic potential of roflumilast against 1,2-dimethylhydrazine (DMH) actuated preneoplastic colon damage in albino Wistar rats.

METHODS

Animals were arbitrarily divided into five groups of six animals each. DMH was used to induce preneoplastic colon damage (20 mg/kg/7 days, subcutaneously, for 42 days). Roflumilast was administered subcutaneously at two doses (1 and 5 mg/kg/day, from day 28 to 42). At the end of the study, the animals were recorded for the electrocardiographic changes and heart rate variability (HRV) paradigms on 42nd day, using PowerLab system. Blood samples were collected from all the animals to measure hydrogen sulfide (H₂S) and nitric acid. The colon tissue was dissected out and analyzed for inflammatory markers, biochemical parameters including, superoxide dismutase, thiobarbituric acid reactive substances, catalase, and glutathione reductase and histopathology.

RESULTS

DMH caused derangement of HRV factors, abnormal antioxidant markers, and elevated levels of inflammatory markers. H₂S and nitric oxide levels upsurge in DMH-treated rats and promoted preneoplastic damage. Histopathologically, loss of crypts, goblet cells, and distorted lamina propria were observed in toxic group. Treatment with roflumilast was able to curtail down oxidative stress and inflammatory markers and stabilitate the hemodynamic derangements as well as was able to restore the normal architecture of colonic mucosa.

CONCLUSION

The findings from the present study conclude that treatment with roflumilast positively modulates the preneoplastic colon damage.

Mitochondrial apoptosis and curtailment of hypoxia-inducible factor-1α/fatty acid synthase: A dual edge perspective of gamma linolenic acid in ER+ mammary gland cancer

Gamma linolenic acid is a polyunsaturated fatty acid having selective anti-tumour properties with negligible systemic toxicity. In the present study, the anti-cancer potential of gamma linolenic acid and its effects on mitochondrial as well as hypoxia-associated marker was evaluated. The effect of gamma linolenic acid was scrutinised against ER + MCF-7 cells by using fluorescence microscopy, JC-1 staining, dot plot assay and cell cycle analysis. The in vitro results were also confirmed using carcinogen (n-methyl-n-nitrosourea) induced in vivo model. The early and late apoptotic signals in the conjugation with mitochondrial depolarisation were found once scrutinised through mitochondrial membrane potential and life death staining after gamma linolenic acid treatment. Gamma linolenic acid arrested the cell cycle in G0/G1 phase with the majority of cell populations in the early apoptotic stage. The translocation of phosphatidylserine was studied through annexin-V FITC dot plot assay. The markers of cellular proliferation (decreased alveolar bud count, histopathological architecture restoration and loss of tumour micro-vessels) were diminished after gamma linolenic acid treatment. Gamma linolenic acid ameliorates the biological effects of n-methyl-n-nitrosourea persuading the mitochondrial mediated death pathway and impeding the hypoxic microenvironment to make a halt in palmitic acid synthesis. SIGNIFICANCE: The present study elaborates the effect of gamma linolenic acid on mammary gland cancer by following mitochondrial-mediated death apoptosis pathway. Gamma linolenic acid also inhibits cell-wall synthesis by the curtailment of HIF-1α and FASN level in mammary gland cancer.

Breathing Signature as Vitality Score Index Created by Exercises of Qigong: Implications of Artificial Intelligence Tools Used in Traditional Chinese Medicine

Rising concerns about the short- and long-term detrimental consequences of administration of conventional pharmacopeia are fueling the search for alternative, complementary, personalized, and comprehensive approaches to human healthcare. Qigong, a form of Traditional Chinese Medicine, represents a viable alternative approach. Here, we started with the practical, philosophical, and psychological background of Ki (in Japanese) or Qi (in Chinese) and their relationship to Qigong theory and clinical application. Noting the drawbacks of the current state of Qigong clinic, herein we propose that to manage the unique aspects of the Eastern 'non-linearity' and 'holistic' approach, it needs to be integrated with the Western "linearity" "one-direction" approach. This is done through developing the concepts of "Qigong breathing signatures," which can define our life breathing patterns associated with diseases using machine learning technology. We predict that this can be achieved by establishing an artificial intelligence (AI)-Medicine training camp of databases, which will integrate Qigong-like breathing patterns with different pathologies unique to individuals. Such an integrated connection will allow the AI-Medicine algorithm to identify breathing patterns and guide medical intervention. This unique view of potentially connecting Eastern Medicine and Western Technology can further add a novel insight to our current understanding of both Western and Eastern medicine, thereby establishing a vitality score index (VSI) that can predict the outcomes of lifestyle behaviors and medical conditions.

Repurposing mechanistic insight of PDE-5 inhibitor in cancer chemoprevention through mitochondrial-oxidative stress intervention and blockade of DuCLOX signalling

BACKGROUND

This study evaluates the anti-cancer effects of Tadalafil (potent PDE-5 inhibitor) in female albino wistar rats against n-methyl n-nitrosourea induced mammary gland carcinogenesis.

METHODS

The animals were selected and randomly divided among four groups and each group contains six animals per group. The animal tissue and serum samples were evaluated for the presence of antioxidant parameters and the cellular morphology was studied using carminic staining, haematoxylin staining and scanning electron microscopy followed by immunoblotting analysis.

RESULTS

On the grounds of hemodynamic recordings and morphology, n-methyl n-nitrosourea treated group showed distorted changes along with distorted morphological parameters. For morphological analysis, the mammary gland tissues were evaluated using scanning electron microscopy, whole mount carmine staining, haematoxylin and eosin staining. The serum samples were evaluated for the evaluation of oxidative stress markers and inflammatory markers. The level of caspase 3 and 8 were also evaluated for the estimation of apoptosis. The fatty acid profiling of mammary gland tissue was evaluated using fatty acid methyl esters formation. The mitochondrial mediated apoptosis and inflammatory markers were evaluated using immunoblotting assay.

CONCLUSION

The results confirm that Tadalafil treatment restored all the biological markers to the normal and its involvement in mitochondrial mediated death apoptosis pathway along with inhibition of inflammatory markers.